Rotary pump



April 2, u c Q F L ROTARY PUMP 2 Sheets-Sheet 1 Filed Oct. 15, 1965 mmnn i I I I I l h I lllll llll llliiinl .3

INVENTORS ULRICH CHRISTOF VON EIFF ANGEL LIRA UGAEDE ATTORNEYS A ril 2, 1968 u. c. v N EIF ETAL 3,375,983

ROTARY PUMP 2 Sheets-Sheet .2

Filed Oct. 15, 1965 0 Wm. rr.

INVENTORS ULRICH CHRISTOF vow EIFF United States Patent Office 3,375,983 Patented Apr. 2, 1968 79,482 17 Claims. (Cl. 241-46) ABSTRACT OF THE DISCLOSURE A pump having a tubular casing defining an inlet at one end and adding an outwardly convergent tangential outlet passage slanting away from the inlet in cooperation with a concentric shaft having a plurality of essentially fiat blades fixed obliquely from the shaft to sweep the interior of the casing. The blades are laterally bent at one or both ends. The pump is particularly adapted for conveying liquids containing solid and semi-solid materials and particularly relates to a new and novel rotary pump for the conveyance of thick pulps, effluents containing fibrous materials, thick slurries, various pastes and liquids containing solid or semi-solid matter with or without simultaneous comminution of the matter in the liquid.

BACKGROUND OF INVENTION Rotary pumps for use in the delivery of liquids containing solids or semi-solids and for the simultaneous comminuting and delivery of fibrous materials or the like are known, in which the impeller of the pump comprises a screw, a helical blade assembly, a propeller or a swashplate journaled in a pump casing or housing for rotation about an axis concentric to the axis of the casing. The edges of such impellers are formed with teeth or teeth means which coact with annular grooves in the casing, the teeth means cooperating with the grooves to disintegrate any solid matter in the material. The pump casing has an axial inlet at one end and a vertical outlet at the other end with the impellers functioning to move the liquid and matter or fibrous materials along the casing from the inlet to the outlet, while simultaneously grinding or comminuting the materials.

Representative of such types of pumps are those disclosed in Neidl Patents Nos. 2,956,503 (Oct. 18, 1960); 3,005,597 (Oct, 24, 1961), 3,067,960 (Dec. 11, 1962); and 3,113,734 (Dec. 10, 1963).

The rotary pumps, which are disclosed in the foregoing patents, include a rotor or an impeller which is in the form of a circular or elliptical disc provided along its periphery with teeth which coact with annular grooves formed in the inside wall of the pump casing or in the inner wall of a liner fitted in the pump casing, which is in the form of a hollow body of revolution. The disc is mounted obliquely on the pump shaft, which is rotatably disposed in the casing concentric to the axis of the casing, and the disc functions to comminute or grind the material by virtue of the coaction of the peripheral teeth or serrated edges with the grooves and to convey the material from the axial inlet to the vertical outlet and deliver it out through the outlet.

Such pumps have decided operational disadvantages as well as constructional disadvantages. For example, such pumps can not develop any appreciable amount of pres sure in the pump chamber since the disc impeller or rotor cannot move the material from the inlet, through the pump chamber to the outlet under a constant, even and smooth pressure. Furthermore, such pumps, because of the particular disc impeller and outlet constructions, cannot force the material through the outlet in a constant,

smooth and forceful manner to a height of any effective consideration above the pump casing. The pumps'cannot develop any considerable pressure with the result that they cannot pump more than a few feet above the pump casing. In addition, there is the tendency for such pumps to become clogged or jammed, when operating on liquids containing heavy solid matter.

Accordingly, an important object of the present invention is to overcome the disadvantages in known rotary pumps of the foregoing type and for use in the simultaneous delivery and comminuting of fibrous materials or liquids containing heavy solid and semi-solid matter by providing a novel rotary pump wherein an extremely high pumping pressure can be developed in the pump chamber so as to realize a delivery of material from the pump to an extremely high height, which is of importance in the use of such a pump in an industrial liquefier mixer having a recirculation system, for example.

Another important object of the present invention is to provide a rotary pump for the simultaneous pumping and comminuting of material, in a liquid or semi-liquid suspension state, along the axis of the pump chamber from an axial inlet at one end of the chamber to a vertical outlet adjacent the other end of the chamber in a manner so that the material is moved under a considerable constant pressure while being ground, torn or comminuted.

Another important object of this invention is to provide a rotary pump of the above type which will not become clogged or jammed, in operation, irrespective of the nature of the material being pumped and simultaneously acted upon by being ground, torn or comminuted.

A further object of the present invention is to provide a rotary pump which includes a novel construction of and functionally coacting impeller and pump casing and outlet means therefor that cooperate in such a manner as to produce a very high pressure in the pump casing from an axial inlet to a vertical outlet and which cooperate to insure free, smooth and fast movement of the material from the inlet to the outlet and through the outlet under high pressure so that the material can be exhausted to a considerable height above the casing, without any tendency of the impeller to become clogged or jammed due to the solid state or nature of any type of material that may be introduced into the pump and acted thereupon.

One novel feature of the pump of the present invention resides in the construction and mounting of blades on the pump shaft which blades constitute the impeller of the pump and which are formed in such a manner that they coact with annular grooves in the inner wall of the pump casing or in a liner mounted on the inner wall of the pump casing or with axial grooves on the wall of the pump casing or on the inner Wall of a liner for more efiicient comminuting action or defibrating action and in the formation of the blades, adjacent the inlet end of the pump casing, in such a manner as to produce considerably higher pressure and consequent faster movement of the material from the inlet to the outlet and discharge of the material through the outlet to a greater height.

Another novel feature of the present invention resides in the novel construction of the outlet means in association with the casing and with the impeller, the outlet means being inclined upwardly and rearwardly from the casing and arranged tangentially thereto with the impeller sweeping over the throat of the outlet means.

It is envisioned by the present invention that the impeller may be essentially composed of two semi-elliptical blades which are mounted obliquely on the pump shaft, which shaft is rotatably disposed within the pump casing or housing, concentric thereto, the blades being flat and straight and having end portions, adjacent the axial inlet end of the pump casing, which end portions are bent outwardly from the shaft toward the liner or inner wall of the casing and, have their extremities at or near approaching points with the liner or inner wall. Such construction of the blades produces a higher pumping pressure and to increase such pumping pressure, it is en visioned that the blades can be counter bent at their other end portions, that is, the end portions opposite the end portions adjacent the inlet of the pump casing or housing. In other words, the opposing end portions of the blades are bent inwardly toward the shaft, whereby the pumping pressure of the impeller is further increased. Such bending and counter bending of the end portions of the blades causes the impeller to discharge the material through the outlet means to a considerable height. In the latter respect, the outlet means is structurally related with the casing and, functionally related thereby with the impeller, so that the material can be moved by the impeller from the pump casing or housing into and through the outlet means in a smooth transition, under high pressures.

A further object of the present invention is to provide a rotary pump which is of simple and sturdy construction and which can be economically manufactured and which has a minimum of simple operating parts of sturdy construction that will efficiently operate for a long and trouble-free time.

The foregoing and ancillary objects and other structural features of merit are attained by the present invention, the preferred embodiments of which are set forth in the following description and illustrated in the accompanying drawings, wherein:

FIGURE 1 is a side elevational view of one form of the novel pump of the present invention;

FIGURE 2 is an end elevational view thereof;

FIGURE 3 is a longitudinal, vertical sectional view taken on line 3-3 of FIGURE 2;

FIGURE 4 is a transverse, cross-sectional view taken substantially on the line 4-4 of FIGURE 3;

FIGURE 5 is a perspective view of the impeller;

FIGURE 6 is a longitudinal, vertical cross-sectional view of another embodiment of the rotary pump of the present invention;

FIGURE 7 is a transverse cross-sectional view taken substantially on the line 7--7 of FIGURE 6;

FIGURE 8 is a perspective view of the impeller, which is used with the pump of FIGURES 6 and 7; and

FIGURE 9 is a fragmentary cross-sectional view of the pump of FIG. 7, showing a further feature of the impeller construction.

Referring now more particularly to the accompanying drawings, and initially to FIGURES 1-5, the rotary pump 10 comprises a casing 12, which is in the form of a hollow body of revolution and, as illustrated, is cylindrical. The casing 12 has an open end 14 and a closed end 16. While the casing is shown as being cylindrical, it may be frustoconical shaped, with the inlet end being constituted by either the minor or the major end of the frusto-conical shaped casing.

The closed end wall 16 of the pump casing or housing 12 rotatably supports a pump shaft 18, which is mounted in bearings 20 suitably housed in an opening in the end wall 16. The shaft 18 is rotatably disposed within the casing concentric with the axis of the casing, and is driven by any suitable prime mover, through the intermediary of any desired drive arrangement. The interior of the casing defines a pump chamber within which the shaft is rotatably positioned. The open end 14 of the casing defines an inlet for the pump chamber, the inlet being axial of the casing and aligned with the pump chamber.

The casing 12 is formed with an outlet means 22, which extends upwardly therefrom and which is inclined rearwardly from the inlet casing from a point back of the inlet 14- and which is disposed tangential to the casing or housing, as shown in FIGURES 1-4. The outlet means 22 includes a front wall 24, which is inclined upwardly and rearwardly from the casing and which extends from a point slightly rearwardly from the inlet end of the casing to any desired height and which confronts a rear wall 26 that extends upwardly and slightly rearwardly from the end wall 16 of the casing. The outlet means 22 further includes opposing side walls 28 and 30 (FIGURE 4), with the side wall 28 extending upwardly from the casing, substantially normal to the axis of the casing and being the outer side wall, and with the side wall 30, which is the inner side wall, extending upwardly and laterally outwardly from the casing at a point substantially coinciding with the center of the shaft 18.

The walls, which make up or form the outlet means 22, may be cast integral with the casing or housing 12 and, therefore, the outlet means 22 may be in one piece construction with the casing, with the walls, that define the outlet means, terminating in a common plane and having a laterally outstanding flange 32, which constitutes a coupling flange for coupling the outlet means or outlet 22 to any desired conduit means (not shown).

The impeller 34, as shown most clearly in FIGURES 3 and 5, essentially comprises a pair of flat, semi-elliptical blades 36 and 38, which are mounted at diametrically opposing points on the shaft 18 and which are disposed obliquely thereto in crossed relation. The illustration of only two blades 36 and 38 is for simplification purposes, since the impeller may be composed of three or more blades, of similar configuration and of similar mounting relationship with the shaft, as the blades 36 and 38, with the plurality of blades being spaced circumferentially around the shaft.

The blades have straight inner edges 40, which are fixed in oblique slots 42 formed in the shaft at diametrically opposed portions and in crossed relation. The blades have arcuate or curved outer edges 44, which complement the body of revolution form of the casing 12.

An annular liner 46 is fitted in the casing and is provided at its outer end with a mounting flange 48 that is secured by fasteners 50 in a recess 52 at the inlet end of the casing. The liner is formed on its inner wall from one end to the other end with annular grooves 54 and the outer edges 44 of the blades are provided with teeth 56 which coact with the grooves in the grinding, tearing or comminuting of the material, as the material is moved or delivered by the rotary action of the blades from the inlet to and through the outlet means 22. Thus, the outer curved edges 44 of the blades are serrated and coact with the annular grooves, which lie in a contiguous arrangement along the length of inner wall of the liner.

The fiat, straight blades 36 and 38 have outer end portions 58 and 60, which are bent out of the planes of the blades and are bent outwardly from the shaft 18 and have their outer free ends or extremities terminating at or in engagement with grooves adjacent the inlet end 14 of the casing. The outwardly bent end portions 58 and 60 of the blades produce a higher pressure in the pump chamber, defined by the liner or in the absence of the liner, by the inner wall of the housing or casing, so that the material is pumped under higher pressure and at a greater flow rate from the inlet 14 to the outlet means 22 and through the outlet means to a considerable height above the casing. Thus, the particular formation of the blades and relationship thereof with the pump shaft and the particularly formed outlet means 22 ensures that the material is moved under a higher pressure in the pump chamber and causes a resultant higher pumping height of the material from the casing.

The liner 46 is formed at the throat 62 of the inlet means 22 with slots 64 that underlie the throat 62 of the inlet means in order to insure that only material, which has been reduced to the desired size, can pass into the outlet means 22. Obviously, the openings will be of various dimensions depending upon the material, that is, the composition and nature and the size of the material that is desired to be permitted to pass from the pump casing and be discharged by the impeller into and through the outlet means 32.

It is to be particularly noted that the blades are mounted in oblique fashion on the pump shaft and are disposed in crossed relation, with the blades having major straight, flat portions that extend from the end wall 16 radially from the shaft 18, from a point adjacent the end wall 16 of the casing and which terminate in outwardly bent end portions 58 and 60 that come into engagement or near engagement with the grooves adjacent the inlet end 14 of the casing.

The toothed or serrated arcuate or curved peripheral edges of the blades sweep over the slotted portion of the liner, that is over the slots 62, and coact with the grooves, thereby achieving grinding and comminuting of the material, Without danger of the blades becoming jammed or clogged, and with a smooth transitional passage of the material into the outlet means under a substantial pressure.

In the absence of the liner, the annular grooves can be formed in the inner wall of the casing and the same result will be realized, with a slotted or perforated plate being fixed at the throat of the outlet means 22. The liner is provided to save wear on the casing, since a replacement liner can easily be installed if needed.

In the embodiment of FIGURES 68, the casing 12a is similar to the casing 12 and the pump casing 12:: has an outlet means 22a, which is similar to the outlet means 22 of the pump 12, shown in FIGURES 14.

, The impeller 34a of the pump a, illustrated in FIG URES 68, is formed so that a counter flow of the liquid mass or fibrous material is produced resulting in a still higher pressure in the pump chamber and, consequently, considerably more pumping height of the material through the outlet means 22a.

As shown in FIGURE 8, the blades 62 and 64 are semielliptical in plan and are flat and straight and are mounted in oblique, crossed fashion on the pump shaft 18a, in a manner similar to the formation and mounting arrangement of the blades 36 and 38. The outer end portions 66 and 68 of the blades, adjacent the inlet end 14a of the pump chamber of the casing 12a are bent outwardly from the pump shaft. The inner or opposing end portions 70 and 72 of the blades are bent inwardly toward the pump shaft 18a, whereby the blades have a counter bend. The counter bending of the inner end portions 70 and 72 produces a counter flow of the liquid resulting in a still higher pressure in the pump chamber. The curved or arcuate peripheral edges 74 of. the blades, which constitute the impeller 32a, are plain and cooperate with longitudinal or axial grooves 76 formed in the inner wall of the liner 78, which is mounted in the pump casing 12a in the same manner as the liner 46. Of course, the grooves 76 can be formed in the inner wall of the pump casing or housing. The grooves 76 extend axially of the shaft and the pump casing from one end of the liner to the other end and the plain arcuate edges 74 of the blades sweep across the grooves resulting in a defibrating action of the pump. Obviously, the grooves can be of any shape desired and can be in closely space relation around the circumference of the inner wall of the liner, as shown, or can be spaced further apart.

In the latter respect, the annular grooves 54 in the liner 46 can be interrupted, along the axis of the liner, so that the grooves are discontinuous to form shearing edges cooperating with the teeth 56 on the arcuate outer edges of the blades 36 and 38.

It can be appreciated that, in either of the forms of the impellers 34 or 34a, the outer end portions are bent outwardly from the rotating pump shaft, within the pump casing or housing, adjacent the inlet of the pump chamber or casing, whereby a higher pressure is realized in the pump chamber, resulting in the smooth transitional forced flow of the material along the chamber from the inlet and into and through the outlet means 22 or 22a,

in association with the casings 12 or 12a and with the impellers 34 or 34a, is of importance in achieving the smooth, high pressure transitional outflow of the material from the pump casing.

It can be appreciated, in the instance of either the blades 36 or 38 or the blades 62 and 64, that the major, arcuate portions thereof are straight and arranged obliquely to the shaft and disposed in crossed relation and that, while only two blades have been shown and described as making up the impellers, any number of blades, similar in form and mounting arrangement, can be used. Of course, the blades 36 and 38 can have their inner ends counter bent, approximating the counter bent end portions 7072. In FIGURE 9, the curved outer edges 74a of the blades shown and used in the pump assembly of FIGS. 6-8 are bent rearwardly relative to the direction of rotation of the impeller and contact the axial grooves in the liner or in the inner wall of the pump casing so as to produce a refining action without cutting the fibers.

Accordingly, while the preferred and best known forms of the present invention have been described herein and illustrated in the accompanying drawings, it is to be understood that other forms can be realized, as come Within the scope and spirit of the appended claims.

What is claimed is:

1. A rotary pump, for use particularly in conveying materials such as efiiuents, thick pulps and fluid suspension solid or semi-solid matter or the like, comprising a casing in the form of a hollow body of revolution, said casing defining a pump chamber and having a side wall and opposing ends, said casing having an inlet at one end and a solid end wall closing off the other end, said casing having an outlet means having first, rear and opposite side walls whose inner surfaces define an outlet passage leading from said chamber, said outlet passage having an axial extent at its intersection with said chamber to extend from adjacent said inlet to said solid end wall and sloping rearwardly from said intersection, and said outlet passage extending substantially tangentially from said chamber, a shaft rotatably mounted in. the casing concentric to the axis of the casing, and an impeller mounted on the shaft and including at least two semi-elliptical fiat blades mounted on the shaft obliquely of the axis of the shaft and disposed in crossed relationship and radially extending from the shaft and extending longitudinally of the casing from the inlet to said solid end wall.

2. A rotary pump, for use particularly in conveying materials, such as effluents, thick pulps and fluid suspension solid or semi-solid matter or the like, comprising a casing in the form of a hollow body of revolution, said casing defining a pump chamber and having a side wall and opposing ends, said casing having an inlet at one end and a solid end wall closing off the other end, said casing having an outlet means which is inclined upwardly and rearwardly therefrom behind the inlet and is disposed tangentially of the casing, a shaft rotatably mounted in the casing concentric to the axis of the casing, and an impeller mounted on the shaft and including at least two semi-elliptical flat blades mounted on the shaft obliquely of the axis of the shaft and disposed in crossed relationship and radially extending from the shaft and extending longitudinally of the casing from the inlet to the outlet means, said blades having end portions disposed adjacent the inlet end of the casing and bent outwardly from the planes of the blades away from the shaft toward the inner surface of the side wall of the casing.

3. The invention of claim 2, wherein said blades have serrated arcuate outer peripheral edges and said casing has an inner peripheral wall formed with annular grooves with which the edges coact in the grinding of the material as it is moved by the blades from the inlet to and through the outlet means.

4. The invention of claim 2, wherein said blades have end portions adjacent the end wall which are bent inwardly out of the planes of the blades and toward the shaft.

5. The invention of claim 2, wherein an annular liner is fixedly mounted in the pump casing and defines the pump chamber and is formed on its inner surface with annular grooves and said blades have curved outer edges formed with teeth which coact with the grooves in grinding the material as the material is moved by the blades from the inlet to and through the outlet means.

6. In the invention of claim 2, wherein said casing has an inner wall formed with axial grooves and said blades have rearwardly bent plain arcuate outer edges coacting with the grooves to produce a refining action simultaneous with the pumping action of the blades.

7. The invention of claim 2, where an annular liner is fixedly mounted in the pump casing and defines the pump chamber and is formed on its inner surface with axial grooves and said blades have rearwardly bent plain curved outer edges which coact with the grooves to produce a refining action as the material is moved by the blades from the inlet to and through the outlet means.

8. The invention of claim 1, wherein said blades have end portions adjacent the inlet, said end portions being bent outwardly from the shaft and terminating adjacent the casing inner wall and have opposing end portions adjacent the end wall of the casing, said opposing end portions being bent inwardly toward the shaft, whereby a counter flow of the liquid in the pump casing is produced.

9 A rotary pump, for use particularly in conveying efiluent materials, comprising a casing in the form of a hollow body of revolution, said casing having a side wall and opposing ends, one of said ends being open and defining an axial inlet, and end wall closing off the other end, said casing having an outlet means disposed behind the inlet and inclined upwardly and rearwardly from the casing in communication with the interior thereof and arranged tangentially of the casing, a shaft rotatably mounted in the casing concentric to the axis thereof, an impeller mounted on the shaft within the casing and including at least two straight flat blades mounted on the shaft obliquely to the axis of the shaft and radially extending from the shaft and extending longitudinally from the inlet to the outlet means, said blades having arcuate outer edges complementing the curvature of the inner surface of the side wall of the casing and having end portions disposed adjacent the inlet end and bent outwardly from the planes of the blades away from the shaft toward the inner surface of the side wall of the casing.

10. The invention of claim 9, wherein said blades have opposing end portions bent inwardly out of the planes of the blades toward the shaft whereby a counter flow of the material in the pump casing is produced.

11. The invention of claim 9, wherein said inner surface of the side wall of the casing is provided with annular grooves and the outer arcuate edges of the blades are serrated to coact with the grooves in comminuting the material as it is conveyed by the blades from the inlet to and through the outlet means.

12. The invention of claim 11, wherein said grooves are formed in the inner surface of an annular liner fitted in the casing against the inner surface of the side wall thereof.

13. The invention of claim 10, wherein said inner surface of the side wall of the casing is provided with axial grooves extending longitudinally from the inlet end to the end wall, and said outer arcuate edges of the blades are plain and cooperate with the grooves to produce a defibrating action simultaneous with the pumping action.

14. The invention of claim 13, wherein said edges of the blades are bent rearwardly relative to the direction of rotation of the impeller.

15. The invention of claim 13, wherein said grooves are formed in the inner surface of an annular liner fitted in the casing against the inner surface of the side wall thereof.

16. The invention of claim 9, wherein said outlet means is composed of a front wall inclined upwardly at an obtuse angle from the casing behind the inlet end, a rear wall slightly inclined upwardly from the end wall of the casing, an outer side wall extending upwardly from one side-of the side wall normal thereto and an inner side wall extending upwardly from the casing and inclined outwardly and extending from the casing at a point above the shaft.

17. The invention of claim 15, wherein said casing has an opening communicating the interior of the casing with the space within the confines of the walls constituting the outlet means and a perforated straining means is interposed between the casing and the space within the confines of said walls.

References Cited UNITED STATES PATENTS 2,265,758 12/1941 Klosson 1031l1 2,619,292 11/1952 Nichols et al 24l46 3,005,597 10/1961 Neidl 103-ll1 X 3,185,100 5/1965 Secrest 103-111 X FOREIGN PATENTS 65,668 7/1928 Sweden.

ANDREW R. JUHASZ, Primary Examiner. 

